1. Field of the Invention
The present invention relates to testing of semiconductor wafers.
2. Description of Related Art
The use of conductive elastic probes for measuring one or more electrical properties of a semiconductor wafer is disclosed in U.S. Pat. No. 6,492,827 to Mazur et al. It has been observed that conductive elastic probes formed from certain materials, such as platinum, iridium or tantalum, or probes having platinum, iridium or tantalum-coated tips work best for testing semiconductor wafers. Heretofore, it was believed that the inability to grow oxides and/or the ability to grow conductive oxides on one or more of these materials rendered them more useful for such testing. However, in accordance with the present invention, it is believed that the work function of the probe surface that presses into contact with a semiconductor wafer during the testing can affect the measurement thereof.
What is, therefore, needed and which is not disclosed in the prior art is a method of measuring at least one electrical property of a semiconductor wafer with a contact or probe wherein at least the contact portion thereof has a controlled work function.